package codingforgreat.lchot150;

public class Lc141 {
 class ListNode {
     int val;
     ListNode next;
     ListNode(int x) {
         val = x;
         next = null;
     }
 }
    public boolean hasCycle(ListNode head) {
        ListNode slow = head;
        ListNode fast = head;
        while( fast != null && fast.next != null){
            fast = fast.next.next;
            slow = slow.next;
            if(slow == fast){
                return true;
            }
        }
        return false;
    }
}
